(1) Technical Field
This invention relates generally to the sorting of wooden boards for building a panel, and more particularly, to the matching of boards by their visual qualities and width dimensions to form panels within a given overall dimension while minimizing color variations between contiguous boards.
(2) Description of the Prior Art
The following six documents relate to methods and apparatus for sorting objects according to their color or size.
U.S. Pat. No. 5,813,542 issued Sep. 29, 1998 to Cohn describes a method of classifying objects by sensing a multiple color image of at least a portion of the object and producing color signals indicative of a plurality of colors in response to sensing the multiple color images.
U.S. Pat. No. 5,351,833 issued Oct. 4, 1994 to B. S. Quick describes a method for selecting wood stock to form panels of predetermined size by automatically selecting and transmitting to further work stations appropriately sized pieces of stock which, when glued together saves time in the formation of an end product.
U.S. Pat. No. 5,533,628 issued Jul. 9, 1996 to Tao describes a color sorting apparatus employing a conveyor which drops the sorted objects into appropriate bins.
U.S. Pat. No. 4,624,571 issued Nov. 25, 1986 to Salda, et al. shows an apparatus for detecting the coloring of moving tiles for the purpose of dividing their flow into a plurality of flows as a function of the quality of their color.
U.S. Pat. No. 4,476,982 issued Oct. 16, 1984 to Paddock, et al. describes a method and apparatus for grading articles, particularly lemons, according to their surface color.
U.S. Pat. No. 4,278,538 issued Jul. 14, 1981 to Lawrence, et al. describes methods and apparatus for sorting work-pieces according to their color signature.
Generally, the steps taken prior to putting together a collection of boards to form a panel of a given overall size, for example, when sorting wood boards for aesthetic blending requires a trained eye to match adjacent boards in a panel array. Dimensional extent, on the other hand, requires a reference standard, or a template to use for measuring or for comparison.
Individual wood species often vary greatly in color. In the process of selecting boards for furniture, cabinetry, and millwork, wood stains are commonly used to produce even-colored wood products. In some cases, a variety of shades of wood stains would be used to blend the color of contiguous boards used for a panel. However, minimizing the use of wood stains that are necessary for esthetic blending would naturally enhance visual quality, and at the same time reduce overall product costs.